Work vehicles, including, but not limited to, agricultural work vehicles such as tractors and combines as well as construction equipment vehicles such as loaders and backhoes, can be configured as articulating vehicles, that is having a pivot intermediate the work vehicle's front end and rear end. A central pivot serves to improve maneuverability of large or long work vehicles. Such work vehicles may be configured using a system of wheels, a system of tracks, or a combination thereof, to propel the work vehicle. The use of a pivot in a work vehicle has many advantages including maneuverability at a work site, such as a farm field or a construction site, and maneuverability on public roads during transport from work site to work site.
Large work vehicles often require a system of steps by which an operator may gain access to the operator station from the ground, or gain access to the ground from the operator station. It is desirable for the system of steps to remain stable and usable throughout operation of the vehicle so that a person may gain access to or exit from the operator station during reasonably slow operation of the work vehicle.
It may be desirable to locate a step assembly adjacent the vehicle pivot. The region adjacent the vehicle pivot provides added complexity in mounting sensitive and complicated equipment due to the vehicles movement in the pivot area. Therefore, due to the simplicity of the step assembly and proximity of pivot region to the operator station, it may be desirable to mount a step assembly in the pivot region.
Placing any equipment in the pivot region provides difficulties because the equipment may interfere with the tires or tracks of the work vehicle when the vehicle makes a turn. Therefore, there is a need for a system of moveable steps whereby the steps move in response to the turn of the work vehicle. For example, if the steps were located on the right side of the tractor adjacent the pivot, a right hand turn would cause interference between the steps and the wheels or tracks of the work vehicle. Therefore, there is a need for a step assembly that moves away from the interference area during a right hand turn. It would be advantageous to have the step assembly remain fixed while the tractor is going substantially in a straight line or during a left hand turn (if the steps are mounted on the right hand side, and right hand turn if the steps are mounted on the left hand side) in which there is no interference between the step assembly and the tracks or wheels.